Mower



' July 27, 1954 P. R. SCHROEPPEL MOWER 6 Sheets-Sheet 1 Original Filed July 14, 1945 INVENTOR July 27, 1954 P. R. scHRbEPPEL MOWER 6 Sheets-Sheet 2 Original Filed July 14, 1945 July 27, 1954 P. R. SCHROEPPEL MOWER Original Filed July 14, 1945 6 Sheets-Sheet 3 INV EN TOR ATTORNEY July 27, 1954 P. R. SCHROEPPEL 2,684,564

INVENTOR @gQW MJKDM July 27, 1954 P. R. SCHROEPPEL MOWER 6 Sheets-Sheet 5 Original Filed July 14, 1945 Jilly 27, 1954 P. R. SCHROEPPEL MOWER Original Filed July 14, 1945 6 Sheets-Sheet 6 lElllllnTu INVENTOR ATTORNEY Patented July 27, 1954 MOWER Paul R. Schroeppel, Rockford, Ill., assignor to J. I. Case Company, Racine, Wis., a corporation of Wisconsin 1 Original application July 14, 1945, Serial No.

605, 04. Divided and this application November15, 1950, SerialNo.195,7 24

6 Claims. 1

The present invention relates to mowers, and more particularly to mowers adapted to be mounted on and carried by tractors, and 'an object of the invention is to generally improve the construction and operation of devices of this class.

This application'is a division of application Serial No. 605,004, filed July 14, 1945, now Patent No. 2,532,426. r

More" particularly, an'object of the invention is to provide a mower which will have an extreme range ofupw'ard and downwardswinging movement' without disturbing the registration of the sickle'with the'guards.

Another object is toprovid'ean improved adjustment for the cutter'bar which will maintain the desired tilt of the'guards in all positions of swinging of the bar and in which adjustments for tilt will not affect the lead of thefcutter bar when" swung to extreme upward or downward positions i Other objects are to provide improved controls for the cutter bar position; an improved drag bar mounting; a greatly improved inner shoe which provides for relief of excessive stress in the event of encountering an obstructiong'and an improved latch arrangement for such a shoe.

Other objects and advantages 'will' become apparent from the following description and ,accompanying drawings, in which "a satisfactory embodimentof the invention'is shown, but it is to be understood that the invention is not limited to the"'exact details disclosedgbut includesfall such variations and modifications asrnr within the spirit of the invention as herein expressed.

In the drawings,

Figure 1 is a plan view of a device constructed according to the invention, in place on a tractor, the tractor being indicated in dotted'lines and broken away to avoid obscuring any mower parts.

Fig.2 is'a' front elevation of the same, parts being broken away and others omittedwhere they formno part of the invention.

Fig. 3 is an enlarged section on'the line 3-3 of Fig. 1.

Fig. 4 is a right side elevation partly in section on the line 44 of Fig. 2, with parts removed.

Fig; 5 is an enlarged detail of certain controls indicated in Fig. 4. Y

Fig. 6 is an enlarged plan view of certain'mech anism indicated in Fig. 1.

Fig. 7 is a similar view with the parts in another position.

Fig. 8 'is a vertical sectional View on the line 8- 8 of Fig. 6.

Fig. 9 is 'a horizontal sectional view on the line 9-9 of Fig. 8.

Fig. 10 is a plan'view of certain parts-indicated in Fig. 8.

Fig. 11 is an'enlarged front elevation of oer tain'mechanism indicated in Fig. 9.

Fig. 12 is a sectional view on the line 12-42 of Fig. 11.

Fig. 13 is a vertical sectional view on the'line l3-l3 of Fig. 8.

Fig. leis an enlarged front elevation of certain mechanism indicated in Fig. 2.

Fig. 15 is a horizontal sectional view on theline l5|5 of Fig. 14.

Fig. 16 is an'enlarged detail taken on the line l6|6 of Fig. 4.

Fig. 17 is a sectional view taken on the line il-ll of Fig. 16. h

Similar reference characters have been-applied to the same parts throughout the drawings and the following specification.

As seen in Fig. l the illustrative device'is shown applied toa tractor'T to which is attached a drag-bar D, which in'turn serves to maintain a cutter bar C correct relation to the tractor through connection with a shoe S fixedly connected with the cutter bar 0. The mechanism of the mower is driven from a power take-ofi P driven from the tractor enginefnot' shown, in well-known manner, an extensible joint shaft E transmitting the motion to mechanism on the shoe, which will be fully'described presently. The mower is thus carried on and operated by the tractor, necessary relative move-'- rnents between the two being accommodated by extensible shaft E, extreme changes in position being possible in cutter bar C without interference with proper driving, aswillappear.

Power take-off P includes a shaft?!) projecting from the rear of tractor T and rotatable from the engine power in well-known manner not necessary to describe further. Shaft 20 carries a pulley 2| driving, through a'belt 22 a pul1ey'23 on a shaft 24. Shaft 24 is carried in a'bearing element 25 supported on a bracket'structure'l fi so as to be shiftable for tightening belt 22, an

adjusting bolt 2'! having lock nuts 28- 28 engaged with bracket 26 being fixed to hearing 25, manipulation of nuts iii- 28' serving to shift bearing 25 in a controlled manner as will be understood. A guard or housing 29 is preferably carried by bracket 26 and encloses the belt and pulleys for reasons of safety."

Shaft '24 connects with a universal joint generally designated as 3!} of suitable or well-known form driving a section 3| having a slidable but non-rotatable connection with a section 32 forming the active element of extensible shaft E. Section 32 connects with a universal joint generally designated as 33 which is preferably similar to above mentioned joint and which connects with a crankshaft 34 best seen in Figs. 8, 9 and 13. An extensible housing of well-known form generally designated as 35 is supported between joints 38 and 33 to enclose the rotating shaft sections 3| and 32.

Crankshaft 34 in the present instance is supported in a needle type roller bearing 36 having rollers 3l3| to reduce friction and provide durable support against the vibration set up in this form of mechanism. Bearing 36 is firmly supported in a lower shoe portion and solidly retained therein by means of a cap 39 fixed to portion 38 as by screws 40- 55. Portion 38 is rotatably mounted on an upper shoe portion 4| to relieve excessive stress in the event of encountering an obstruction, as will appear. Cutter bar C is fixedly attached to portion 33 by bolts or the like 42-42 which also retain in position a guide 43 for a knife-head 44 constituting part of a sickle 45. A complementary guide 46 for knifehead 44 is retained on portion 38 by bolts 4'|4'|. Knife-head 44 connects by a ball joint 48 with a pitman 49 having a hinged connection 58 to a crank pin bearing 5| engaging a crank pin 52 carried by a crank disk 53 fixed on above mentioned crankshaft 34. It is to be noted that crankshaft 34 and ball joint 48 are substantially on a level so that pitman 49 swings above and below the extended path of travel of the joint 48.

Since crank 53 turns counterclockwise as seen in Fig. 13, the resultant pressure on knife-head 44 as a consequence of the sickle actuating movement is always down on the cutter bar, thus minimizing the strain and wear on guides 43 and 46 and avoiding the development of up-and-down play and rattling of the sickle. Since crankshaft bearing 36 is rigidly mounted on shoe portion 38, which in turn is solidly fixed to cutter bar C, it follows that the motion of sickle will always be the same relatively to cutter bar C and guards 54 regardless of any position that portion 38 may take. Universal joint 33 provides for the transmission of motion to crankshaft 34 throughout the possible range of movement of portion 38.

The present mower is particularly adapted for difiicult conditions such for example as mowing the shoulders of highways where extreme upward and downward angles of the cutter bar are required. Such angularity may be achieved without disturbing the other adjustments of the mower. as will appear. Upper portion 4| is pivoted about a journal portion 55 of drag bar D, and which journal portion is directed, and remains, substantially parallel with the direction of travel of the tractor. Portion 4| swings about this journal, all angular adjustments of the shoe being accomplished without changing the position of the journal. A part-spherical bearing portion 55 is fixed on journal 55 on which is seated a socket portion 51 of above mentioned portion 4|, the whole forming a suitable type of pivot bearing for the shoe S. Socket portion 5! continues as a sleeve portion 5! enclosing journal 55 and formed larger than said journal so as to provide a clearance area 51 Spaced from portion 57! a bushing 58 is rotatably received in a bore 59 in a cap-like fitting 65 and has a bore 6! which is eccentric to above mentioned bore 59. Fitting 65 is fixed with portion 4| so that shifting of bushing 58 will alter the position of portion 4| about spherical portion 56. In this way the cutter bar may be angled forward or back relatively to drag bar D so that the lead may be adjusted.

Fitting 60 is clamped immovably in contact with a surface 62 on shoe portion 4|, which is curved about the center of spherical portion 56 so that relative movement of portion 4| and fitting 60 will result in angular adjustment of cutter bar C so as to tilt guards 54 upwardly or downwardly as desired. Fitting 66 is clamped in position by a bolt 63 engaged with portion 4| and maintaining, by means of a nut 64, a block 65 in clamping engagement with fitting 60, the latter and block 65 having interfitting teeth and notches 66 to positively locate fitting 60 when nut 64 is tightened. It will now be apparent that bushing 58 and fitting 68 constitute adjustable bearing means which can be adjusted at least to a limited extent in any direction laterally of or substantially normal to the axis of sleeve 51*, to the extent permitted by the clearance area 51 As will now be apparent, shifting or bushing 58 for adjusting the lead of cutter bar C will also affect the tilt of the bar, but this is compensated for by loosening nut 64 and shifting portion 4| relatively to fitting 60, after which the parts are locked in position by tightening nut 54. Bushing 58 is fixed in position in fitting 60 by means of a flange 61 having a series of notches 68-68 one of which is engaged by a pin 69 projecting from fitting 60. Bushing 58 is disengaged from the pin by moving slightly to the right as seen in Fig. 9, and turning as by means of a wrench to the desired position. Bushing 58 is preferably given an angular outward configuration to facilitate this. A nut 78 on journal portion 55 presses bushing 58 backwardly against portion 4|, thus keeping flange 61 in engagement with pin 69 and maintaining socket portion 5! seated on spherical portion 56. Washers l0 are preferably interposed between nut 10 and bushing 58 and a locking pin 10* Fig. 9, maintains the adjustment of nut Ill. It will now be apparent that, although portion 4|, and accordingly cutter bar C can be adjusted in any direction relatively to drag bar D, it always swings about the center-line of journal portion 55. Thus unlike prior structures which depend on adjustment of the drag bar for lead or tilt adjustment, or both, lead is not converted to tilt, and vice versa, when the cutter bar is swung into extreme upper or lower positions.

As above mentioned, lower portion 38 of shoe S is pivotally carried by upper portion 4|, and in the event of encountering an obstruction by cutter bar C, may turn thereon, allowing cutter bar C to swing back and relieve the stress, thus saving the parts from damage. For this purpose upper portion 4| has a pintle carried by a bracket 12 permanently secured to portion 4|, said pintle establishing a vertical center line about which portion 38 may swing. Portion 4| also has a circumferential guiding flange 13, a

circumferential guiding surface 74, and, preferably, a guiding groove 15. Lower portion 38 has a surface 16 complementary to flange l3 and a guiding plate Tl, surface 15 and plate ll enclosing flange 73 and guiding portion 38 in relation thereto. Portion 38 also has a portion 18 engaging pintle H to maintain portion 38 centered on portion 4|. Portion 38 is formed complementary to surface 14 and above mentioned cap portion 39 preferably has a rib l9 engaging groove 15. The

above described parts are so fitted as to provide for free pivoting of portion 38 about pintle II, and portion 41 has a slot 80, providing for movement of bearing 36 with portion 38. Cutter bar C can therefore swing back if it encounters an obstruction, swinging portion 38 about pintlc II and on its several guiding surfaces, but it will be noted that this swinging does not affect the rela tion of crankshaft 3,4. to sickle 45, nor the registration or stroke of the sickle.

It is necessary to prevent such pivoting of portion 33 under normal operation and a detent generally' designated as 80 is provided for this purpose. In the present instance, oap 39, Fig. 8, has

an upstanding portion 8| extending beyond rib 1-9 and having a notch 82 engaged by a latch 83, see also Figs. 6 and '7, pivoted on a. pin 84 carried by ears as '85 on upper portion 4|. Latch 83 is held in position by a tension rod 86 having a T head 81 onwhich is, journaled a bifurcated cam lever 08 pressed against latch 83 by. the pull of rod 86. Rod 06 is tensioned by a spring 89, Fig. 8. A nut and washer anchor spring 89 to rod 86, and T head 87 is preferably threaded on rod 86 as shown. Swinging cam lever '88 to the dotted position shown in Fig. 6 releases the tension in rod 86, and, while so released, if cam lever 88 is rotated about rod 86 T head 81 will be shifted along rod 86' so that when the rod is again tensioned the adjustment will be different than before. In this manner the tension is readily controlled. When the tension is released as stated, cutter bar C may be readily swung back for ready access to pitman 4'9 and bearing or for other reasons. A stop 0| on plate 11 engages a stop 92 on flange I3 at the limit of back-swinging of portion 4|, and a stop 93 engages the outer edge of flange I3 when portion 38 is in normal position. Therefore it is not necessary to rely on latch 83 except to hold the parts against swinging back under normal loads.

While latch 83 is sufilcient for this purpose. it is sometimes desirable, for example when mowers of this type are made with long heavy cutter bars, to have additional resistance against swinging back. In this event an opening or socket 94' is provided in flange I3 and a detent as for example a ball 95 is pressed by a spring 96 contained in a tubular housing 91 through a suitable open,- ing in plate TI into yielding engagement with opening 94. Housing N is anchored to plate TI. The pressure of spring 96 is adjusted by a screw 98 threaded in a cap 09- forming an upper closure for housing 9?. Sufiicient turning effort on portion 38 and plate II will dislodge detent 95 from opening 04 after which the detent will travel along the surface of flange I3 without causing appreciable resistance. The pressure necessary to so dislodge detent 05 will assist latch 83- so that the latter need not be adjusted so tightly in the event that an unusually long cutter bar is used. Furthermore, in the event of extreme loads of this sort the resistance to swinging is applied at two substantially diametrically opposite points, which tends to equalize the pressure on pintle II and the several guiding surfaces. Detent 95 can be given an approximate adjustment, and the exact desired resistance arrived at by adjusting T head 87.

Drag bar D includes a bar I00, Fig. 1, and a bar IOI, the two being united in V relation and serving to support above mentioned journal portion 05 in fixed relation to the line of travel of the tractor T. Bar I00 extends transversely beneath the tractor substantially at right angles to the path of movement while bar I M extends laterally and forwardly from a bracket I02 fixed on the tractor in any suitable'manner as by'bolts I02 and isjoined' at I02 tobar I00. 'A brace I03 is extended between bars I00 and IN to form a comparatively rigid triangular'structure and to furnish an attaching point for certain mechanism as will appear. Drag bar D must be free to swing up and down to allow shoe s to follow uneven ground, and for'this reason bar IOI is pivoted to bracket I 02 at I04, while bar I00 is pivoted to 'a bracket I05 at I06. Due to the substantialspacing between pivots I04 and I06, journal is held firmly in'place without any appreciable tendency to swing back under the drag of the cutter bar.

In the present instance, pivotal connections I04 and I06 are of a special nature as best shown in Fig. 3, the two being identical, it is necessary to describe only one. Bar IOI is'pivote'd on a stud I01 carried by above mentioned bracket I02 and terminates in a ring-like eye portion I08 which extends about a stud I01 and is spaced therefrom by a bushing I09 and a body of rubber or rubberlike material I I0. Material I I0 is compressed axially of stud I01 between a washer I I I and a cap II! by means of a nut II 3 threaded on stud I07. This compression tends to extrude a portion of material I I0 between the open ends of eye I08 and Washer III" and cap II! respectively, so that eye I08 is cushioned in all directions from any metallic contact with stud I01 or bracket I02. Upand-down swinging of bar IOIis relatively freely accommodated by turning bushing I09 on stud I 01 or bydistortion of the rubber-like material or both. These cushioned pivotal connections I04 and I06 serve to absorb a large amount of vibrationnormally present in 'a sickle drive and minimize pounding and wear of the parts. They also tend to isolate such vibrations from the tractor to an appreciable extent so as tominimize discomfort to the operator.

The type of mower disclosed as stated is particularly adapted for mowing the shoulders on highways where it is necessary to raise and lower shoe S quickly, for example to place it'on a curb, to avoid culvert headings and the like, and it is also necessary to quickly swing cutter bar 0 to a substantially vertical position to pass mail boxes, avoid roadside fences and the like. These operations are under extremely close control by fluid pressure as will now appear.

A suitable source of fluid pressure of any well known type, not shown, is disposed on the tractor and supplies fluid through a pipe II which leads to control valves generally designated as I I5 and I I6 which may be-of any suitable or wellknown type having operating handles I I! and i I9 respectively. The valves are biased to a neutral position by means of springs I I 0I I9 and under these conditions the fluid flows to the valves through above mentioned pipe I I4 and returns to the supply through a hose or other conduit I20. There being no substantial pressure developed, no appreciable amount of power is consumed by this action. When itis desired to lift a part of the mower, the valves upon proper manipulation of one or the otherof handles II! and I I8, interrupt the flow of fluid into conduit I20 whereupon pressure is immediately developed in pipe I I4 and transmitted through connections IZI or I22 to actuate lifting rams as will appear directly. Release of' handles II! and H8 blocks the escape of fluid backwardly' through connections I2 I and I22 so that therarns are held in whatever position they have reached while fluid is again permitted to bypass through conduit I29. Actuation of either handle III or H8 in the opposite direction releases fluid from either connection I2I or I22 to conduit I29 and allows the ram connected to a particular conduit to retract. Valves H and IIIi in the present instance are mounted on a plate I23 supported on the tractor in a convenient position for ready manipulation by the op= erator. Plate I23 in the present instance is fixed with the tubular column I24 fixed with a bracket I25 rigidly mounted on the tractor. For lifting shoe S, a flexible connection as chain I26 is extended from above mentioned brace I53 upwardly to a bifurcated tension member or yoke I21. Yoke I21 may be raised with the necessary degree of force by means of a cylinder I28 disposed within the yoke as better seen in Fig. 14. Cylinder I23 is seated on a pedestal I29 in the present instance carried by a portion of above mentioned bracket I25 and has a base portion I36 slotted to serve as a guide for side portions I3I and I32 of yoke I21. Cylinder I28 has a ram I33 actuated by a piston I34 within cylinder I28 and connected to side portions I3I and I32 by means of a bolt I35, spacers as I36 serving to locate ram I33 properly within yoke I21. Side portions I3I and I32 approach each other above bolt I35 and are united as by a bolt I31. In this manner a tension memher is provided having suflicient strength to lift drag bar D and shoe S. Side portion I32 has an outwardly extending ear I38 to which is connected a retracting spring I39 anchored to above mentioned brace I03 as best seen in Fig. 1. Spring I39 exerts a continuous downward pressure on yoke I21 and maintains piston I34 at the bottom of cylinder I28 at such times as fluid pressure is not transmitted to cylinder I28. Pressure is transmitted when desired through above mentioned connection I2I to cylinder I23. Piston I34 being at its lowermost position, yoke I21 is so placed as to result in substantial slack in chain I26. Thus shoe S is free to float on uneven ground without interference from any part of the lifting connection.

A counterbalancing spring I49 extends transversely of the tractor and upwardly from brace I63 to an anchorage IIII, Fig. 1, on above men tioned bracket I95 and is attached to an adjusting bolt I42 having a nut I43 for adjusting the tension of spring I40 as will be apparent. Spring E43 thus carries part of the weight of shoe S so as to avoid excessive ground pressure.

Upward swinging of cutter bar C is accomplished in a somewhat similar manner, a chain or flexible connection I44 engaging a pin I45 best shown in Fig. 2 spaced upwardly and outwardly from above mentioned journal 55 this portion of the shoe constituting an upwardly directed lever I45a. Chain I44 is connected to a yoke generally designated as I46 within which is positioned a fluid cylinder I41. Pressure fluid transmitted through connection I22 to cylinder I41 shifts yoke I45 to the right as seen in Fig. 2 thereby pivoting shoe S in a clockwise direction about journal 55. This action can swing cutter bar C to a substantially vertical position within the margins of a tractor wheel I48 so that the mower in this position will clear anything which the tractor will clear.

Turning to Fig. 16, cylinder I41 has a base portion I49 slotted for slidably receiving side portions I50 and I5I of yoke I45. Cylinder I41 also has a ram I52 which is coupled to side portions I50 and I5I by means of a bolt I53 in a manner similar to the connection of above mentioned ram I33. Spaced from base I49 is an abutment I54 extending outwardly from above mentioned bar I90 as best seen in Fig. 1'7, abutment I54 being slotted for slidably supporting side portions I and I5I of yoke I46. Ram I52 has a piston I55 slidable in cylinder I41 and, when pressure fluid is introduced into connection I22, cylinder I41 is first forced to the left in Fig. 16 until base I49 rests against abutment I54. Further movement of cylinder I41 is thus blocked and piston I55 then moves to the right forcing with it ram I52 and yoke I49. This exerts sufficient tension on chain I44 to pivot shoe S and rock outter bar C upwardly as stated. When fluid is released through connection I22, the weight of cutter bar C moves yoke I46 to the left along with piston I55. However, in order to completely expel the fluid from cylinder I41, a spring I56 attached to a finger I51 extending from base I49 forces cylinder I41 to the right to the position shown in Fig. 16. Spring I55 is anchored to a bracket I58 fixed on the tractor. It will now be apparent, that spring I55 maintains cylinder I41 in its extreme right position in Fig. 16 and exerts a gentle tension on yoke I45 and chain I44. Up-and-down movement of cutter bar C is accommodated by the necessary to-and-fro motion of yoke I45 together with cylinder I41, this motion never being sufficient to seat base I49 on abutment I54. In this manner, the cutter bar is allowed to float over uneven ground without interference from cylinder I41.

An assisting spring I59 is pivoted to an ear I63 on shoe S outwardly and above journal 55 and tensioned between above mentioned bracket I58 and ear I60. The pull of spring I59 thus exerts a continuous turning moment on shoe S in a cutter bar raising direction. An adjusting bolt I6I may be manipulated in known manner to adjust the tension in spring I59 so as to avoid unnecessary pressure in cylinder I41 while not interfering with prompt lowering of the bar when desired.

The operation of the invention has been described where it would facilitate an understanding of the construction and further description should be unnecessary except to say that the mower bar projects at one side of the tractor for the usual purposes and may be swung upwardly substantially instantly upon manipulation of valve control lever IIB as necessary for avoiding obstructions such as fences and mail boxes and downwardly equally promptly when the obstructions are passed. This upswinging has not effect on the registration of the sickle since crankshaft 34 is journaled on the same portion of shoe S which swings with cutter bar C. In case it is desired to lift shoe S as necessary for avoiding curbs and the like, this may be done substantially instantly by manipulation of valve control lever I I1. In case an obstruction is encountered, latch 93 releases and cutter bar C swings back to the position indicated in Fig. 7 so as to relieve the parts from injury. Again this does not affect the registration since crankshaft 34 remains in the same relation with cutter bar C and swings with it. Detent 95 assists latch 33 in holding cutter bar C in operative position if necessary.

The above being a complete description of an illustrative embodiment of the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a mower of the type including a shoe, a cutter bar fixedly connected to the shoe, a crankshaft mounted for rotation on the shoe in fixed relation to the cutter bar, a sickle on the cutter bar, a pitman connected between the crankshaft and sickle, said shoe being mounted for upand-down swinging movement about a center line extending generally in the direction of travel, said cutter bar, said sickle, said pitman and said crankshaft swinging together about said center line without disturbing their relations with each other, the improvement which comprises a portion journaled for rotation about said center line and adjustably fixed with said shoe for predetermining the position of said shoe relatively to said axis.

2. In a mower an inner shoe for the mower having a lower movable part and an upper relatively stationary part to which said movable part is pivoted on a substantially vertical axis, said stationary part being swingable on an axis extending substantially in the direction of progress of the mower, and a portion journaled on the last mentioned axis and adjustably fixed with said inner shoe for predetermining the position of said shoe relatively to said axis.

3. In a mower an inner shoe for the mower having a lower movable part fixed with the cutter bar and an upper relatively stationary part to which said movable part is pivoted on a substantially vertical axis, said stationary part being swingable on an axis extending substantially in the direction of progress of the mower, said parts embodying juxtaposed circumferential guiding flanges, said flanges having openings being so located as to register when said movable and stationary parts are in normal operative position, a spring pressed detent slidable in one of said openings and projecting into the other opening and resisting relative movement of said movable and stationary portions suiliciently to prevent such movement but so constituted as to be forced out of said other opening upon application of excessive pressure tending to pivot said movable part.

4. In a mower an inner shoe having a lower movable part and an upper relatively stationary part to which said movable part is pivoted on a substantially vertical axis, said stationary part being swingable on an axis extending substantially in the direction of progress of the shoe, said movable part having a portion upstanding alongside of said stationary part so as to move in a circular path upon pivoting of said movable part, a spring-pressed detent on said stationary part positioned to engage said upstanding portion and prevent pivoting of said movable part about said substantially vertical axis, said parts embodying juxtaposed circumferential guiding flanges, said flanges having openings so located 1i) as to register when said movable and stationary parts are in normal operative position, a springpressed detent in one of said openings engaging the other opening and resisting relative movement of said movable and stationary portions at a point substantially circumferentially spaced from the above mentioned detent, said detents being disengageable upon application of excessive pressure tending to pivot said movable part.

5. In a tractor mounted mower having a drag bar pivoted to the tractor on a longitudinal axis, a shoe pivoted to the drag bar and a cutter bar connected to the shoe, an arm portion extending upwardly from the shoe, a yoke fiexibly attached to the arm portion and slidably supported from the drag bar, a fluid pressure cylinder slidably supported within the yoke and having a ram connected with the end of the yoke remote from the flexible connection with said arm portion, an abutment on the drag bar spaced from the cylinder, spring means connected with the cylinder and so disposed as to urge the cylinder away from the abutment to force the ram into the cylinder and to urge the yoke away from the shoe whereby swinging of the shoe about the drag bar is provided by sliding of the yoke and cylinder relatively to the drag bar, application of fluid to the cylinder first forcing the cylinder against the abutment and subsequently forcing the yoke relatively to the drag bar in a direction to rotate the shoe about its pivotal connection to the drag bar for raising said cutter bar.

6. In a tractor mounted mower having a drag bar pivoted to the tractor on a longitudinal axis and a shoe carried by the drag bar, a support on the tractor, a yoke slidable in an up-and-down direction relatively to the support, a fluid pressure cylinder on the support and having a ram extending upwardly and connected with the top of the yoke, a flexible connection from the bottom of the yoke to the drag bar and spring means connected with the yoke and disposed to exert a downward pressure thereon whereby to force the ram into the cylinder and maintain the yoke in its lowermost position except when pressure fluid is introduced into the cylinder.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,946,543 Paul Feb. 13, 1934 1,958,405 Anthoney et al. May 15, 1934 2,204,334 Wagner June 11, 1940 2,291,987 Rogers Aug. 4, 1942 2,311,095 Simpson et al Feb. 16, 1943 2,328,838 Obellink Sept. 7, 1943 2,495,986 Schroeppel Jan. 31, 1950 

